Solution for 2013 "First Model With Bathroom" Holding Tank Overflowing Into Shower

AldebaranJill

I have a 2013 T@B Max, one of the first models to have a bathroom/shower. This model has a 19 gallon combined black/grey water holding tank. Unfortunately, way before you reach 19 gallons, the holding tank overflows into bathroom via the shower drain, leaving you standing in your own poop water while taking a shower. Not optimal. From my tests, this happens somewhere around 10 gallons, give or take a few.

The reason, is because while the toilet and kitchen sink drain directly into the holding tank, the bathroom sink and shower floor have separate pipes, that join into one larger 1.5" pipe, that runs alongside the holding tank, finally joining it just behind the dump gate valve. The system is configured in such a way that the shower drain is literally below the upper level of the holding tank.

I called the factory, and spoke to a very nice fellow who informed me, with clear apology, that yes, my arrangement is one of the earliest attempts at integrating a bathroom/shower, and well, they've learned a lot since. I was told now they have separate holding tanks for grey water and black water, but that converting mine into that configuration would really be cost prohibitive. I spent some time brainstorming with him, and given the very small usage of my sink and how showering is well planned - asked him if I simply added a gate valve into the long 1.5" pipe - to prevent backflow of sewage, would that cause any other unforeseen issues, and he said no, it sounded like a good solution.

I next consulted Dale, since he has more experience with RV plumbing, and asked about a check valve vs gate valve, and he preferred the gate valve idea for reliability and simplicity - he wasn't sure a check valve would open. I ordered a 1.5" Black ABS Gate Valve (Valterra) from Amazon.

I went to Home Depot and purchased a bit of extra 1.5" ABS, a T, and fittings to make the T output to a garden hose (3/4").

I've completed the mod, and tested it fully. I can now put in 21 gallons before I see water through the toilet opening. I can either open the new gate to allow my bathroom grey water to enter the tank (if it's below 10 gallons) or collect it into a bucket. I wanted to document this in the event that someone else out there has a 2013 model with a single 19 gallon combined holding tank, and is tired of poop water in their shower. :-)


Artist's rendering of my system showing single combined grey/black water tank, and the separate smaller 1.5" pipe that drains (or fills with poop water) the shower and bathroom sink. I added a gate valve and grey water drain outlet in the middle of this 1.5" pipe.


1.5" Valterra Gate Valve from Amazon
Other fittings from Home Depot


Fully assembled. Off to the left is where the main 4" dump gate valve is, and off to the right is my sink/bathroom shower drain.


I decided to try out a garden hose valve on the end. Will see if this stays on while traveling or if I have to make it more permanent.



Form the front, showing the main 4" gate dump valve, and the new smaller 1.5" gate valve modification.

Dalehelman

Nice write up Jill.

ericnliz

AldebaranJill, Good solution for a "stinker" of a problem.  Really nice write up, and a relatively simple solution to a problem that seemed to slip by the research & development department. [no offense intended] Thanks for sharing, and hopefully it will help others with the same set-up. Dalehelman is definitely the guy I would have gone to as well after consulting with the factory. Believe me, we're very lucky to have him so close for advise & consulting on various head scratching modifications and ideas.  

Dalehelman

Eric, thanks for the kind words. I love to help if I can, And I learn so much as well.

ericnliz

Dale, 

JerryandVicki

Jill, we are very impressed with your solution to that nasty problem.  It is brilliant and you are to be commended for lying on your back under your Tab, in the driveway, working on the sewer all the while Seattle was being inundated by that nasty overhead river last week. 

You have turned your lemons to sweet lemonade, and now have the largest black water holding tank (almost 19 gallons) than anyone else in the fleet.  Plus, you still have a way to use your shower while achieving that 19 gallons.  Hmmm.  19 gallons vs 5 gallons.  What a no brainer.   

AldebaranJill

JerryandVicki said:

Jill, we are very impressed with your solution to that nasty problem.  It is brilliant and you are to be commended for lying on your back under your Tab, in the driveway, working on the sewer all the while Seattle was being inundated by that nasty overhead river last week. 

You have turned your lemons to sweet lemonade, and now have the largest black water holding tank (almost 19 gallons) than anyone else in the fleet.  Plus, you still have a way to use your shower while achieving that 19 gallons.  Hmmm.  19 gallons vs 5 gallons.  What a no brainer.   

  

And I did the mod while wearing my 10lb orthopedic broken foot boot!

When I took my trailer in to my dealer yesterday, I showed them this mod. The fellow told me a story about a similar issue in another brand of RV - same situation, had connected the black water and grey water in such a way that black water backed up into the shower. He loved the mod. :-)

Ratkity

You poor thing!!! With an orthopedic foot brace to boot! (couldn't.resist.pun). Excellent solution! My old popup just had a garden hose drain for gray water to dump in a bucket or wheeled gray tank (never saw those until last few years, btw). 

Marceline

@AldebaranJill
How is this working out for you?
I just bought a 2013 T@B CSS and I couldn't figure out where the gray tank release is.
Now I know why. I'm not sure that it would have been a deal breaker but I wish I'd known.

AldebaranJill

The mod continues to work out very well for me. Having a 19 gallon black/grey water tank can be advantageous at times. Very happy with it. I replied to your private message. Sorry for delay, was out camping without cell service.

Marceline

Thanks Jill!

Rbarbee

Hi Jill,
I have a 2013 CSS with shower and single dump valve. I would like to make this modification as well. I’m trying to understand, where is the water going when showering if the added gate valve is closed? Maybe I’m just missing something.

Thanks, Robert

AldebaranJill

When using the shower the new valve must be open to allow flow into tank. So you only take showers when holding tank is empty (or at a level that adding shower water won’t cause to overflow). For me, I use 2-3 gal for a shower so my holding tank needs to have a max of 6 gallons to avoid overflow.

Marceline

AldebaranJill said:

When using the shower the new valve must be open to allow flow into tank. So you only take showers when holding tank is empty (or at a level that adding shower water won’t cause to overflow). For me, I use 2-3 gal for a shower so my holding tank needs to have a max of 6 gallons to avoid overflow.

Or you can send it to a bucket, right? 

(Now regretting that I was too chicken to implement this mod)

AldebaranJill

Send the shower water to a bucket? 

In theory, but the outlet is very low and really not bucketable.